Field of the Invention
The present invention relates to a storage battery apparatus including a battery such as a lithium secondary battery, a lead battery, a nickel-hydrogen battery, and an electric double layer capacitor, and an electric power apparatus, a distributed electric power storage apparatus, and a hybrid electric vehicle which mount such storage battery apparatus.
Background Art
Because of the gas emission regulation and improvement of fuel consumption, a hybrid electric vehicle has been actively developed which uses a secondary battery as an auxiliary assist power for an engine. A lithium secondary battery and a nickel-hydrogen battery have been often used as this secondary battery for a vehicle. A secondary battery used as a battery of a hybrid electric vehicle is used for assist of an engine (assist in case of acceleration), and supplies electric power to a motor in case that the vehicle is driven only with the motor on a flat road as suspending the engine. Thus, because large electric power is supplied to the motor, the supply to the motor reduces the electric power of this secondary battery, so that the electric power is generated by using a motor for the driving to charge the secondary battery as is necessary.
As described above, a secondary battery used for a battery of a hybrid electric vehicle frequently repeats charging and discharging, the calorific value of the charging and discharging of this secondary battery is large, and the battery performance is temperature-dependent, so that it is necessary to increase the cooling-performance of the battery in consideration of the life of the battery. Up to now, there have been many proposals for increasing such cooling-performance of a battery.
Thus, as illustrated in FIG. 9, the Patent Document 1 (JP Patent Publication (Kokai) No. 2001-155789) discloses a storage battery apparatus which conventionally changes shapes of assistant ribs forming the first to the seventh louver 28a to 28g to narrow flow paths of cooling air to increase the flow speed of the cooling air as it approaches a cooling air discharging side 27, eliminates the temperature variation between tandem cells, causes the cooling air to join directly from bypaths to the air whose temperature has risen as flowing between the tandem cells to suppress the temperature rise of the tandem cells around the cooling air discharging side 27, and equally cools the whole tandem cells.
In addition, the Patent Document 2 (JP Patent Publication (Kokai) No. 2003-109637) discloses a technique which detects the temperature difference of cooling medium at an entry and an exit of a fuel cell module, and when it exceeds a prescribed value, determines the status of a fuel cell system and a cooling system. However, even if the temperature difference of cooling medium at an entry and an exit of a fuel cell module is detected, it is not enough for deciding the status of the cooling system, and it is not possible to determine the status of a temperature detection unit.
An object of the present invention is to provide a storage battery apparatus including a highly reliable cooling system which can diagnose the status of a cooling unit and a temperature detection unit.